Abstract On glacial-interglacial and millennial timescales, sea ice is an important player in the circulation and primary productivity of high latitude oceans, affecting regional and global biogeochemical cycling. In the modern North Pacific, brine rejection during sea-ice freezing in the Sea of Okhotsk drives the formation of North Pacific Intermediate Water (NPIW) that ventilates the North Pacific Ocean at 300 m–1000 m water depth. Glacial intervals of the late Quaternary, however, experienced a deepening of glacial NPIW to at least 2000 m, with the strongest ventilation observed during cold stadial conditions of the last deglaciation. However, the origin of the shifts in NPIW ventilation is poorly understood. Numerical simulations suggest an atmospheric teleconnection between the North Atlantic and the North Pacific, in response to a slowdown or shutdown of the Atlantic meridional overturning circulation. This leads to a build-up of salinity in the North Pacific surface ocean, triggering deep ventilation. Alternatively, increased sea-ice formation in the North Pacific and its marginal seas may have caused strengthened overturning in response to enhanced brine rejection. Here we use a multi-proxy approach to explore sea-ice dynamics, sedimentary redox chemistry, and benthic ecology at Integrated Ocean Drilling Program Site U1343 in the eastern Bering Sea across the last 40 ka. Our results suggest that brine rejection from enhanced sea-ice formation during early Heinrich Stadial 1 locally weakened the halocline, aiding in the initiation of deep overturning. Additionally, deglacial sea-ice retreat likely contributed to increased primary productivity and expansion of mid-depth hypoxia at Site U1343 during interstadial conditions, confirming a vital role of sea ice in the deglacial North Pacific carbon cycle.

中文翻译：

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白令海东部晚第四纪海冰和沉积氧化还原条件——对北太平洋中深度通风和大西洋-太平洋跷跷板机制的影响

摘要 在冰期-间冰期和千年时间尺度上，海冰是高纬度海洋环流和初级生产力的重要参与者，影响区域和全球生物地球化学循环。在现代北太平洋，鄂霍次克海海冰冻结期间的盐水排斥驱动了北太平洋中间水 (NPIW) 的形成，使北太平洋在 300 m–1000 m 水深通风。然而，第四纪晚期的冰川间隔经历了冰川 NPIW 加深至至少 2000 米，在最后一次冰消的寒冷状态下观察到的通风最强。然而，人们对 NPIW 通风变化的起源知之甚少。数值模拟表明北大西洋和北太平洋之间存在大气遥相关，以应对大西洋经向翻转环流的放缓或关闭。这导致北太平洋表层海洋盐度增加，引发深层通风。或者，北太平洋及其边缘海中海冰形成的增加可能会导致强烈的倾覆，以响应增强的盐水排斥。在这里，我们使用多代理方法来探索过去 40 ka 白令海东部综合海洋钻探计划站点 U1343 的海冰动力学、沉积氧化还原化学和底栖生态。我们的研究结果表明，在早期 Heinrich Stadial 1 期间，由于海冰形成增强而导致的盐水排斥使盐层局部减弱，有助于引发深部倾覆。此外，